When you give a player a potion or tipped arrow with custom effects, it doesn't give the name of the effect. So doing:

/give @p minecraft:tipped_arrow 1 0 {CustomPotionEffects:[{Id:15,Amplifier:0,Duration:60}]}

gives you a blindness potion, but it doesn't show Arrow of Blindness, it shows Arrow of splashing, which is really weird. Same occurs with a potion, instead of it being Potion of Blindness, it's Splash Water bottle; not sure if I'm using an incorrect datatag or what.